1850 bce

Construction

The Egyptian national water administration occupies a building south of Memphis that has about 3000 rooms. It is nicknamed the Labyrinth. Some of it is below ground and, according to Herodotus, contains the graves of kings and sacred crocodiles.

An enormous irrigation project for the Fayum desert region is begun by Pharaoh Sesostris II and completed by Ammenemes II. A canal 90 m (300 ft) wide carries water from the Nile to a 1735-sq-m (670-sq-mi) natural depression in the Fayum. Flow of water is controlled by a dam with sluice gates. See also 6000 bce Food & agriculture; 1750 bce Food & agriculture.

Mesopotamian mathematicians discover what is now known as the Pythagorean theorem. See also 2000 bce Mathematics.